Devices for dispensing the contents of collapsible tubes have been known in the art for many years. Each of these previous devices utilizes some form of winding key or knob arrangement, operated by two hands, to dispense the contents of the collapsible tube by rotating the dispenser in the direction of the tube's neck. For example, U.S. Pat. Nos. 1,986,409, 1,990,929, 2,492,594, 4,570,828, and 4,653,670 all utilize the fundamental winding key concept. U.S. Pat. Nos. 3,473,698, 3,759,421, 3,885,708, and 4,576,314 add a tapered guide for compressing the tube as it is wound around the dispenser. U.S. Pat. No. 4,664,293 employees an anti-unwinding feature which is especially useful in dispensing the contents of plastic tubes.
In order to dispense the contents of the collapsible tube into a uniform bead, these prior art devices require the use of two hands to simultaneously hold and rotate the dispenser so as to maintain a constant pressure within the tube. It is quite difficult however to maintain this continuously even pressure while concurrently rotating the dispenser.
If only one hand is employed, it is almost impossible to dispense a uniform bead for a prolonged period of time. One reason for this is that it is extremely strenuous and tiring to maintain a constant pressure on the tube.
This is particularly true in the case of tubes containing thick fluids such as industrial caulks, sealers, glues and the like. Further, the contents tend to move in multiple directions within the tube as pressure is applied, thus requiring the application of even greater pressure over a larger surface area of the tube.
This movement problem is exacerbated when a significant portion of the contents of the tube is depleted. Additionally, only a small portion of the contents of the tube can be dispensed before the process must necessarily stop and the dispenser again be rotated toward the neck of the tube. Each of these factors can result in both a reduced and uneven discharge rate and the consequent lack of uniformity in the dispensed bead.